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Codebook for NHGIS data file 'nhgis0025_ts_nominal_county'
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Contents
    - Data Summary
    - Data Dictionary
    - Geographic Integration Methods
    - Source Data
    - Citation and Use
 
Detailed notes on time series design and comparability are available at: 
    https://www.nhgis.org/sites/www.nhgis.org/files/nhgis_time_series_tables.pdf 
 
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Data Summary
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Time series layout:     Time varies by row
Geographic level:       County (by State)
Geographic integration: Nominal
Measurement times:      1970, 1980, 1990, 2000, 2010, 2008-2012, 2015-2019, 2020
 
Tables:
 
1. Total Population
   Valid years in file: 1970, 1980, 1990, 2000, 2010, 2008-2012, 2015-2019, 2020
   Code: AV0
 
2. Persons by Race [6*]
   Valid years in file: 1980, 1990, 2000, 2010, 2020
   Code: AA0
 
3. Persons of Hispanic or Latino Origin
   Valid years in file: 1970, 1980, 1990, 2000, 2010, 2020
   Code: A35
 
4. Persons by Nativity [2]
   Valid years in file: 1970, 1980, 1990, 2000, 2008-2012, 2015-2019
   Code: AT5
 
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Data Dictionary
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Context Fields 
        GISJOIN:     GIS Join Match Code
        YEAR:        Row Source Year
        STATE:       NHGIS Integrated State Name
        STATEFP:     FIPS State Code
        STATENH:     NHGIS Integrated State Code
        COUNTY:      NHGIS Integrated County Name
        COUNTYFP:    FIPS County Code
        COUNTYNH:    NHGIS Integrated County Code
        NAME:        Year-Specific Area Name
 
Table 1: (AV0) Total Population
        AV0AA:       Persons: Total
 
Table 2: (AA0) Persons by Race [6*]
        AA0AA:       Persons: White (single race)
        AA0AB:       Persons: Black or African American (single race)
        AA0AC:       Persons: American Indian and Alaska Native (single race)
        AA0AD:       Persons: Asian and Pacific Islander (single race)
        AA0AE:       Persons: Some Other Race (single race)
        AA0AF:       Persons: Two or More Races
 
Table 3: (A35) Persons of Hispanic or Latino Origin
        A35AA:       Persons: Hispanic or Latino
 
Table 4: (AT5) Persons by Nativity [2]
        AT5AA:       Persons: Native
        AT5AB:       Persons: Foreign born
 
Margins of Error 
(Provided for American Community Survey data only) 
 
Table 1: (AV0) Total Population
        AV0AAM:      Margin of error: Persons: Total
 
Table 2: (AT5) Persons by Nativity [2]
        AT5AAM:      Margin of error: Persons: Native
        AT5ABM:      Margin of error: Persons: Foreign born
 
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Geographic Integration Methods
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Nominal Integration:

    Nominally integrated tables link geographic units across time according to
    their names and codes, disregarding any changes in unit boundaries. The
    identified geographic units match those from each census source, so the
    spatial definitions and total number of units may vary from one time to
    another (e.g., a city may annex land, a tract may be split in two, a new
    county may be created, etc.). The tables include data for a particular
    geographic unit only at times when the unit's name or code was in use,
    resulting in truncated time series for some areas.
    
    Users should be cautious when interpreting changes in nominally integrated
    time series because a single unit code may refer to distinctly different
    areas at different times. If you are uncertain whether any boundaries
    changed in your areas of interest, we recommend inspecting NHGIS GIS files
    to confirm. (NHGIS supplies GIS boundary files for all units and years in
    nominally integrated time series *except* 1970 places and county
    subdivisions.)
    
    Alternatively, for some topics and time periods, NHGIS provides
    "geographically standardized" time series, which provide data from multiple
    times for a single census's geographic units (e.g., 2000 and 2010 data for
    2010 census units). A disadvantage of standardized time series is that, in
    areas where source units do not nest perfectly within a unit of the standard
    year (e.g., where a source 2000 unit intersects multiple 2010 units), NHGIS
    applies interpolation to standardize the data, a process which may
    occasionally produce substantial errors.

Complete documentation on time series integration methods is available at:
    https://www.nhgis.org/documentation/time-series
 
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Source Data
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Additional documentation on NHGIS data sources is available at:
    https://www.nhgis.org/documentation/tabular-data

Table 1: (AV0) Total Population
 
    Time series AA: Persons: Total
        Year: 1970
            Source dataset: 1970 Census: Count 4Pa - Sample-Based Population Data
                Source table: NT126. 100% Population
                    Universe: Persons
                        Variable: [C1I001] Total
        Year: 1980
            Source dataset: 1980 Census: STF 1 - 100% Data
                Source table: NT1A. Persons
                    Universe: Persons
                        Variable: [C7L001] Total
        Year: 1990
            Source dataset: 1990 Census: STF 1 - 100% Data
                Source table: NP1. Persons
                    Universe: Persons
                        Variable: [ET1001] Total
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP001A. Total Population
                    Universe: Persons
                        Variable: [FL5001] Total
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P1. Total Population
                    Universe: Total population
                        Variable: [H7V001] Total
        Year: 2008-2012
            Source dataset: 2012 American Community Survey: 5-Year Data [2008-2012, Block Groups & Larger Areas]
                Source table: B01003. Total Population
                    Universe: Total population
                        Variable: [QSP001] Total
        Year: 2015-2019
            Source dataset: 2019 American Community Survey: 5-Year Data [2015-2019, Block Groups & Larger Areas]
                Source table: B01003. Total Population
                    Universe: Total population
                        Variable: [ALUB001] Total
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P1. Race
                    Universe: Total population
                        Variable: [U7B001] Total
 
 
Table 2: (AA0) Persons by Race [6*]
 
    Time series AA: Persons: White (single race)
        Year: 1980
            Source dataset: 1980 Census: STF 3 - Sample-Based Data
                Source table: NT12. Race
                    Universe: Persons
                        Variable: [DFB001] White
        Year: 1990
            Source dataset: 1990 Census: STF 1 - 100% Data
                Source table: NP6. Race
                    Universe: Persons
                        Variable: [EUY001] White
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP007A. Population by Race
                    Universe: Persons
                        Variable: [FMR001] White alone
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P3. Race
                    Universe: Total population
                        Variable: [H7X002] White alone
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P1. Race
                    Universe: Total population
                        Variable: [U7B003] Population of one race: White alone
 
    Time series AB: Persons: Black or African American (single race)
        Year: 1980
            Source dataset: 1980 Census: STF 3 - Sample-Based Data
                Source table: NT12. Race
                    Universe: Persons
                        Variable: [DFB002] Black
        Year: 1990
            Source dataset: 1990 Census: STF 1 - 100% Data
                Source table: NP6. Race
                    Universe: Persons
                        Variable: [EUY002] Black
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP007A. Population by Race
                    Universe: Persons
                        Variable: [FMR002] Black or African American alone
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P3. Race
                    Universe: Total population
                        Variable: [H7X003] Black or African American alone
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P1. Race
                    Universe: Total population
                        Variable: [U7B004] Population of one race: Black or African American alone
 
    Time series AC: Persons: American Indian and Alaska Native (single race)
        Year: 1980
            Source dataset: 1980 Census: STF 3 - Sample-Based Data
                Source table: NT12. Race
                    Universe: Persons
                        Variable: [DFB003] American Indian, Eskimo and Aleut: American Indian
                        Variable: [DFB004] American Indian, Eskimo and Aleut: Eskimo
                        Variable: [DFB005] American Indian, Eskimo and Aleut: Aleut
        Year: 1990
            Source dataset: 1990 Census: STF 1 - 100% Data
                Source table: NP6. Race
                    Universe: Persons
                        Variable: [EUY003] American Indian, Eskimo, or Aleut
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP007A. Population by Race
                    Universe: Persons
                        Variable: [FMR003] American Indian and Alaska Native alone
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P3. Race
                    Universe: Total population
                        Variable: [H7X004] American Indian and Alaska Native alone
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P1. Race
                    Universe: Total population
                        Variable: [U7B005] Population of one race: American Indian and Alaska Native alone
 
    Time series AD: Persons: Asian and Pacific Islander (single race)
        Year: 1980
            Source dataset: 1980 Census: STF 3 - Sample-Based Data
                Source table: NT12. Race
                    Universe: Persons
                        Variable: [DFB006] Asian and Pacific Islander: Japanese
                        Variable: [DFB007] Asian and Pacific Islander: Chinese
                        Variable: [DFB008] Asian and Pacific Islander: Filipino
                        Variable: [DFB009] Asian and Pacific Islander: Korean
                        Variable: [DFB010] Asian and Pacific Islander: Asian Indian
                        Variable: [DFB011] Asian and Pacific Islander: Vietnamese
                        Variable: [DFB012] Asian and Pacific Islander: Hawaiian
                        Variable: [DFB013] Asian and Pacific Islander: Guamanian
                        Variable: [DFB014] Asian and Pacific Islander: Samoan
                        Variable: [DFB015] Asian and Pacific Islander: Other
        Year: 1990
            Source dataset: 1990 Census: STF 1 - 100% Data
                Source table: NP6. Race
                    Universe: Persons
                        Variable: [EUY004] Asian or Pacific Islander
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP007A. Population by Race
                    Universe: Persons
                        Variable: [FMR004] Asian alone
                        Variable: [FMR005] Native Hawaiian and Other Pacific Islander alone
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P3. Race
                    Universe: Total population
                        Variable: [H7X005] Asian alone
                        Variable: [H7X006] Native Hawaiian and Other Pacific Islander alone
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P1. Race
                    Universe: Total population
                        Variable: [U7B006] Population of one race: Asian alone
                        Variable: [U7B007] Population of one race: Native Hawaiian and Other Pacific Islander alone
 
    Time series AE: Persons: Some Other Race (single race)
        Year: 1980
            Source dataset: 1980 Census: STF 3 - Sample-Based Data
                Source table: NT12. Race
                    Universe: Persons
                        Variable: [DFB016] Other (race N.E.C.): Spanish
                        Variable: [DFB017] Other (race N.E.C.): Not Spanish
        Year: 1990
            Source dataset: 1990 Census: STF 1 - 100% Data
                Source table: NP6. Race
                    Universe: Persons
                        Variable: [EUY005] Other race
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP007A. Population by Race
                    Universe: Persons
                        Variable: [FMR006] Some other race alone
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P3. Race
                    Universe: Total population
                        Variable: [H7X007] Some Other Race alone
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P1. Race
                    Universe: Total population
                        Variable: [U7B008] Population of one race: Some Other Race alone
 
    Time series AF: Persons: Two or More Races
        Year: 1980
            *NOT AVAILABLE for this time*
        Year: 1990
            *NOT AVAILABLE for this time*
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP007A. Population by Race
                    Universe: Persons
                        Variable: [FMR007] Two or more races
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P3. Race
                    Universe: Total population
                        Variable: [H7X008] Two or More Races
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P1. Race
                    Universe: Total population
                        Variable: [U7B009] Population of two or more races
 
 
Table 3: (A35) Persons of Hispanic or Latino Origin
 
    Time series AA: Persons: Hispanic or Latino
        Year: 1970
            Source dataset: 1970 Census: Count 4Pb - Sample-Based Population Data with Race/Ethnicity Breakdown
                Source table: NT24. Spanish Indicator
                    Universe: Persons
                        Variable: [C11001] Any of five Spanish categories of the question on "origin or descent"
        Year: 1980
            Source dataset: 1980 Census: STF 1 - 100% Data
                Source table: NT9A. Persons of Spanish Origin
                    Universe: Persons of Spanish Origin
                        Variable: [C9F001] Total
        Year: 1990
            Source dataset: 1990 Census: STF 1 - 100% Data
                Source table: NP8. Persons of Hispanic Origin
                    Universe: Persons of Hispanic Origin
                        Variable: [EU0001] Total
        Year: 2000
            Source dataset: 2000 Census: SF 1a - 100% Data [Areas Larger Than Block Groups]
                Source table: NP004A. Population by Hispanic or Latino and Not Hispanic or Latino
                    Universe: Persons
                        Variable: [FMC001] Hispanic or Latino
        Year: 2010
            Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
                Source table: P4. Hispanic or Latino Origin
                    Universe: Total population
                        Variable: [H7Y003] Hispanic or Latino
        Year: 2020
            Source dataset: 2020 Census: P.L. 94-171 Redistricting Data Summary File
                Source table: P2. Hispanic or Latino, and Not Hispanic or Latino by Race
                    Universe: Total population
                        Variable: [U7C002] Hispanic or Latino
 
 
Table 4: (AT5) Persons by Nativity [2]
 
    Time series AA: Persons: Native
        Year: 1970
            Source dataset: 1970 Census: Count 4Pb - Sample-Based Population Data with Race/Ethnicity Breakdown
                Source table: NT23. Nativity by Mother Tongue
                    Universe: Persons
                        Variable: [C10001] Native >> English
                        Variable: [C10002] Native >> French
                        Variable: [C10003] Native >> Swedish
                        Variable: [C10004] Native >> German
                        Variable: [C10005] Native >> Polish
                        Variable: [C10006] Native >> Russian
                        Variable: [C10007] Native >> Hungarian
                        Variable: [C10008] Native >> Yiddish
                        Variable: [C10009] Native >> Italian
                        Variable: [C10010] Native >> Spanish
                        Variable: [C10011] Native >> Portuguese
                        Variable: [C10012] Native >> All other
                        Variable: [C10013] Native >> Not reported
        Year: 1980
            Source dataset: 1980 Census: STF 3 - Sample-Based Data
                Source table: NT33. Nativity and Place of Birth
                    Universe: Persons
                        Variable: [DG6001] Native: Born in state of residence
                        Variable: [DG6002] Native: Born in different state
                        Variable: [DG6003] Native: Born abroad, at sea, etc.
        Year: 1990
            Source dataset: 1990 Census: STF 3 - Sample-Based Data
                Source table: NP42. Place of Birth
                    Universe: Persons
                        Variable: [E3N001] Native (001-099): Born in State of residence
                        Variable: [E3N002] Native (001-099): Born in other State in the United States (001-059): Northeast (009, 023, 025, 033-034, 036, 042-044, 050)
                        Variable: [E3N003] Native (001-099): Born in other State in the United States (001-059): Midwest (017-020, 026-027, 029, 031, 038-039, 046, 055)
                        Variable: [E3N004] Native (001-099): Born in other State in the United States (001-059): South (001, 005, 010-014, 021-022, 024, 028, 037, 040, 045, 047-048, 051-052, 054)
                        Variable: [E3N005] Native (001-099): Born in other State in the United States (001-059): West (002-004, 006-008, 015-016, 030, 032, 035, 041, 049, 053, 056-059)
                        Variable: [E3N006] Native (001-099): Born outside the United States (060-099): Puerto Rico (072-075)
                        Variable: [E3N007] Native (001-099): Born outside the United States (060-099): U.S. outlying area (060-071, 076-099)
                        Variable: [E3N008] Native (001-099): Born outside the United States (060-099): Born abroad of American parent(s)
        Year: 2000
            Source dataset: 2000 Census: SF 3a - Sample-Based Data [Areas Larger Than Block Groups]
                Source table: NP021A. Nativity
                    Universe: Persons
                        Variable: [GI8001] Native
        Year: 2008-2012
            Source dataset: 2012 American Community Survey: 5-Year Data [2008-2012, Tracts & Larger Areas]
                Source table: B05012. Nativity in the United States
                    Universe: Total population in the United States
                        Variable: [Q3J002] Native
        Year: 2015-2019
            Source dataset: 2019 American Community Survey: 5-Year Data [2015-2019, Tracts & Larger Areas]
                Source table: B05012. Nativity in the United States
                    Universe: Total population in the United States
                        Variable: [AL5M002] Native
 
    Time series AB: Persons: Foreign born
        Year: 1970
            Source dataset: 1970 Census: Count 4Pb - Sample-Based Population Data with Race/Ethnicity Breakdown
                Source table: NT23. Nativity by Mother Tongue
                    Universe: Persons
                        Variable: [C10014] Foreign born >> English
                        Variable: [C10015] Foreign born >> French
                        Variable: [C10016] Foreign born >> Swedish
                        Variable: [C10017] Foreign born >> German
                        Variable: [C10018] Foreign born >> Polish
                        Variable: [C10019] Foreign born >> Russian
                        Variable: [C10020] Foreign born >> Hungarian
                        Variable: [C10021] Foreign born >> Yiddish
                        Variable: [C10022] Foreign born >> Italian
                        Variable: [C10023] Foreign born >> Spanish
                        Variable: [C10024] Foreign born >> Portuguese
                        Variable: [C10025] Foreign born >> All other
                        Variable: [C10026] Foreign born >> Not reported
        Year: 1980
            Source dataset: 1980 Census: STF 3 - Sample-Based Data
                Source table: NT33. Nativity and Place of Birth
                    Universe: Persons
                        Variable: [DG6004] Foreign born
        Year: 1990
            Source dataset: 1990 Census: STF 3 - Sample-Based Data
                Source table: NP42. Place of Birth
                    Universe: Persons
                        Variable: [E3N009] Foreign born (100-999)
        Year: 2000
            Source dataset: 2000 Census: SF 3a - Sample-Based Data [Areas Larger Than Block Groups]
                Source table: NP021A. Nativity
                    Universe: Persons
                        Variable: [GI8002] Foreign born
        Year: 2008-2012
            Source dataset: 2012 American Community Survey: 5-Year Data [2008-2012, Tracts & Larger Areas]
                Source table: B05012. Nativity in the United States
                    Universe: Total population in the United States
                        Variable: [Q3J003] Foreign-Born
        Year: 2015-2019
            Source dataset: 2019 American Community Survey: 5-Year Data [2015-2019, Tracts & Larger Areas]
                Source table: B05012. Nativity in the United States
                    Universe: Total population in the United States
                        Variable: [AL5M003] Foreign-Born
 
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        IPUMS National Historical Geographic Information System: Version 16.0 
        [dataset]. Minneapolis, MN: IPUMS. 2021. 
        http://doi.org/10.18128/D050.V16.0

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